Author: imp Date: Tue Dec 17 00:13:35 2019 New Revision: 355835 URL: https://svnweb.freebsd.org/changeset/base/355835
Log: Add BIO_SPEEDUP Add BIO_SPEEDUP bio command and g_io_speedup wrapper. It tells the lower layers that the upper layers are dealing with some shortage (dirty pages and/or disk blocks). The lower layers should do what they can to speed up anything that's been delayed. The first use will be to tell the CAM I/O scheduler that any TRIM shaping should be short-circuited because the system needs blocks. We'll also call it when there's too many resources used by UFS. Reviewed by: kirk, kib Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D18351 Modified: head/sys/geom/geom.h head/sys/geom/geom_io.c head/sys/sys/bio.h Modified: head/sys/geom/geom.h ============================================================================== --- head/sys/geom/geom.h Tue Dec 17 00:13:30 2019 (r355834) +++ head/sys/geom/geom.h Tue Dec 17 00:13:35 2019 (r355835) @@ -343,6 +343,7 @@ void g_io_deliver(struct bio *bp, int error); int g_io_getattr(const char *attr, struct g_consumer *cp, int *len, void *ptr); int g_io_zonecmd(struct disk_zone_args *zone_args, struct g_consumer *cp); int g_io_flush(struct g_consumer *cp); +int g_io_speedup(size_t shortage, u_int flags, size_t *resid, struct g_consumer *cp); int g_register_classifier(struct g_classifier_hook *hook); void g_unregister_classifier(struct g_classifier_hook *hook); void g_io_request(struct bio *bp, struct g_consumer *cp); Modified: head/sys/geom/geom_io.c ============================================================================== --- head/sys/geom/geom_io.c Tue Dec 17 00:13:30 2019 (r355834) +++ head/sys/geom/geom_io.c Tue Dec 17 00:13:35 2019 (r355835) @@ -340,6 +340,42 @@ g_io_zonecmd(struct disk_zone_args *zone_args, struct return (error); } +/* + * Send a BIO_SPEEDUP down the stack. This is used to tell the lower layers that + * the upper layers have detected a resource shortage. The lower layers are + * advised to stop delaying I/O that they might be holding for performance + * reasons and to schedule it (non-trims) or complete it successfully (trims) as + * quickly as it can. bio_length is the amount of the shortage. This call + * should be non-blocking. bio_resid is used to communicate back if the lower + * layers couldn't find bio_length worth of I/O to schedule or discard. A length + * of 0 means to do as much as you can (schedule the h/w queues full, discard + * all trims). flags are a hint from the upper layers to the lower layers what + * operation should be done. + */ +int +g_io_speedup(size_t shortage, u_int flags, size_t *resid, struct g_consumer *cp) +{ + struct bio *bp; + int error; + + KASSERT((flags & (BIO_SPEEDUP_TRIM | BIO_SPEEDUP_WRITE)) != 0, + ("Invalid flags passed to g_io_speedup: %#x", flags)); + g_trace(G_T_BIO, "bio_speedup(%s, %zu, %#x)", cp->provider->name, + shortage, flags); + bp = g_new_bio(); + if (bp == NULL) + return (ENOMEM); + bp->bio_cmd = BIO_SPEEDUP; + bp->bio_length = shortage; + bp->bio_done = NULL; + bp->bio_flags |= flags; + g_io_request(bp, cp); + error = biowait(bp, "gflush"); + *resid = bp->bio_resid; + g_destroy_bio(bp); + return (error); +} + int g_io_flush(struct g_consumer *cp) { Modified: head/sys/sys/bio.h ============================================================================== --- head/sys/sys/bio.h Tue Dec 17 00:13:30 2019 (r355834) +++ head/sys/sys/bio.h Tue Dec 17 00:13:35 2019 (r355835) @@ -53,6 +53,7 @@ #define BIO_CMD1 0x07 /* Available for local hacks */ #define BIO_CMD2 0x08 /* Available for local hacks */ #define BIO_ZONE 0x09 /* Zone command */ +#define BIO_SPEEDUP 0x0a /* Upper layers face shortage */ /* bio_flags */ #define BIO_ERROR 0x01 /* An error occurred processing this bio. */ @@ -69,6 +70,9 @@ #define PRINT_BIO_FLAGS "\20\7vlist\6transient_mapping\5unmapped" \ "\4ordered\3onqueue\2done\1error" + +#define BIO_SPEEDUP_WRITE 0x4000 /* Resource shortage at upper layers */ +#define BIO_SPEEDUP_TRIM 0x8000 /* Resource shortage at upper layers */ #ifdef _KERNEL struct disk; _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
